I have tested with glusterfs-6.0-46.el8rhgs, with volume options set on the primary and secondary volume optimal for Virtual Machines images store use case. I could observe that all the files are synced to secondary volume
Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory (glusterfs bug fix and enhancement update), and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. https://access.redhat.com/errata/RHBA-2020:5603